A reader asks why his new gourami appears to be hiding in his tank...
Q: I bought a Peacock gourami and introduced it into the tank in the same way as I always do when adding new fish. It has been in the tank now for three days and I have only seen it once — it doesn’t even show up for food. Is there anything I can do?
ROB POTTER, VIA EMAIL
Bob responds: 'Peacock gourami' is an occasionally used common name for the Dwarf gourami, Trichogaster lalius, so I'm assuming this is the fish you are asking about. You don't mention the size of your tank, the gourami’s tank mates or what sort of decor and planting you have, but all of these can be factors in the secretive and shy behaviour you mention.
Dwarf gourami can be spooked by overly boisterous tank mates or bullied by larger fish. Other gourami species will also usually not tolerate each other in smaller aquariums, so this could be an issue. Similarly, they like plenty of plant growth, particularly floating plants if possible, to make them feel secure and at home. Overly bright lighting can also make them seek shelter as can the location of your aquarium — tanks in busy areas can lead to the fish being startled by people passing by.
I have found Dwarf gourami to be quite variable in temperament (usually a sign of some degree of intelligence), with some being very bold and others relatively secretive. It may just be that you have a shyer, more retiring fish that will take a while to settle into its new surroundings. It's also worth remembering that, while I wouldn't recommend keeping these fish in groups in all but the largest aquaria, it's likely that up until it was moved to your tank it had spent its life in the company of its own kind, so suddenly going solo might have been a bit of a shock.
A few choice food treats such as frozen bloodworm may help tempt it out of hiding. Finally, good water quality is essential, so check your tank’s parameters and consider water changes if you have an elevated nitrate level.